THE BOTANY OF CHRISTMAS ISLAND. 265 



In the commencement of the afforestation of an Oceanic 

 Island, it is obvious that the first terrestrial birds who bring 

 the seeds of such fruit as they eat must perish of starvation or 

 less probably fly on to other places where they can get food. 

 It is only when food has become plentiful by the growth of the 

 seeds birds have brought that the frugivorous birds can settle 

 down in an island. 



In Cocos Island there seem to be no frugivorous birds, 

 nor can the Pteropus occasionally finding its way there survive 

 its voyage. (Forbes wanderings p. 32). Pteropus however can 

 subsist very well on shoots of trees as well as fruits. 



In Cocos Island there are no fruits suitable for frugivor- 

 ous birds except those of a few introduced plants so that birds 

 requiring food of this nature would hardly be likely to survive 

 a long voyage to the island. 



I made some experiments in the Botanic Gardens in 

 Singapore with fruit-eating birds, to discover if possible how 

 long they retained the seed of fruits they had swallowed before 

 passing them. 



A Cassowary was fed with fruits of the Cocoplum (Chry- 

 sobalanvs Icaco) at 9.20 a.m. and passed the seed after 8 p.m. but 

 before morning. 



A Hornbill fed with Cocoplum passed the seed at the 

 same time as the Cassowary. It ate berries of Rhodamnia tri- 

 nervia at 10 a.m. and passed some of the seed at 12, and the rest 

 at 2 p.m. It ate fruits of Carissa carandas at 7 a.m. and passed 

 some at 8 a.m. the rest at 1 p.m. 



Myristicivora, the white pigeon known as the Rawai was 

 unable to swallow seed of the Cocoplum or that of the Rambu- 

 tan, Nephelium lappaceum. It ate Rhodamnia fruits at 10 a.m. 

 and passed all the seed at once at 1 p.m. It ate fruits of 

 Pinanga kuhlit at 8.30 a.m. and began to passs them at 10 

 a.m. continuing till it passed the last at 4 p.m. Carissa fruits, 

 it swallowed at 7 and passed the seed at 8 a.m and 1 p.m. as 

 did the Hornbill. 



It was observed that when fed with much fruit, and these 

 birds passed the seed more slowly than when they had but 

 little given them. . 



R. A. Soc, No. 45, 1905. 



